Wuzi Yanzong Pill protects neural tube defects by activating PI3K/Akt signaling pathway.

Neural tube defects (NTDs) are severe congenital malformations that can lead to lifelong disability. Wuzi Yanzong Pill (WYP) is an herbal formula of traditional Chinese medicine (TCM) that has been shown to have a protective effect against NTDs in a rodent model induced by all-trans retinoic acid (atRA), but the mechanism remains unclear. In this study, the neuroprotective effect and mechanism of WYP on NTDs were investigated in vivo using an atRA-induced mouse model and in vitro using cell injury model induced by atRA in Chinese hamster ovary (CHO) cells and Chinese hamster dihydrofolate reductase-deficient (CHO/dhFr) cells. Our findings suggest that WYP has an excellent preventive effect on atRA-induced NTDs in mouse embryos, which may be related to the activation of the PI3K/Akt signaling pathway, improved embryonic antioxidant capacity, and anti-apoptotic effects, and this effect is not dependent on folic acid (FA). Our results demonstrated that WYP significantly reduced the incidence of NTDs induced by atRA; increased the activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and content of glutathione (GSH); decreased the apoptosis of neural tube cells; up-regulated the expression of phosphatidylinositol 3 kinase (PI3K), phospho protein kinase B (p-Akt), nuclear factor erythroid-2 related factor (Nrf2), and b-cell lymphoma-2 (Bcl-2); and down-regulated the expression of bcl-2-associated X protein (Bax). Our in vitro studies suggested that the preventive effect of WYP on atRA-treated NTDs was independent of FA, which might be attributed to the herbal ingredients of WYP. The results suggest that WYP had an excellent prevention effect on atRA-induced NTDs mouse embryos, which may be independent of FA but related to the activation of the PI3K/Akt signaling pathway and improvement of embryonic antioxidant capacity and anti-apoptosis.

An optimal combination of five main monomer components in Wuzi Yanzong Pill that prevents neural tube defects and reduces apoptosis and oxidative stress.

ETHNOPHARMACOLOGICAL RELEVANCE: Wuzi Yanzong Pill (WYP) is a classic traditional Chinese medicine (TCM) formula that is used for reproductive system diseases. Previous studies showed that WYP had a preventive effect on the development of neural tube defects (NTDs) induced by all-trans retinoic acid (atRA) in mice. AIM OF THE STUDY: This study aimed to determine the optimal combination of main monomer components in WYP on preventing NTDs and to understand the underlying mechanism. MATERIALS AND METHODS: An optimal combination was made from five representative components in WYP including hyperoside, acteoside, schizandrol A, kaempferide and ellagic acid by orthogonal design method. In a mouse model of NTDs induced by intraperitoneal injection of atRA, pathological changes of neural tube tissues were observed by Hematoxylin & Eosin (HE) staining, neural tube epithelial cells apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL), protein changes related to apoptosis, anti-apoptosis, and antioxidant factors were detected with Western blot. Potential targets and mechanisms of monomer compatibility group (MCG) acting on NTDs were analyzed by bioinformatics. RESULTS: Treatment with different combinations of WYP bioactive ingredients resulted in varying decreases in the incidence of NTDs in mice embryos. The combination of MCG15 (200 mg/kg of hyperoside, 100 mg/kg of acteoside, 10 mg/kg of schizandrol A, 100 mg/kg of kaempferide and 1 mg/kg of ellagic acid) showed the most significant reduction in NTD incidence. Mechanistically, MCG15 inhibited apoptosis and oxidative stress, as evidenced by reduced TUNEL-positive cells, downregulation of caspase-9, cleaved caspase-3, Bad, and Bax, and upregulation of Bcl-2, as well as decreased MDA and increased SOD, CAT, GSH, HO-1, and GPX1 levels. Bioinformatics analysis showed that MCG15 acted on the PI3K/Akt signaling pathway, which was confirmed by Western blot analysis showing increased expression of p-PI3K, p-Akt/Akt, and Nrf2 related indicators. CONCLUSION: We have identified an optimal combination of five bioactive components in WYP (MCG15) that prevented NTDs in mice embryos induced by atRA by activating the PI3K/Akt signaling pathway and inhibiting apoptosis and oxidative stress.